If you don't say anything to anyone about your campaign, the chances people to know you and your idea simply diminishes. You will have to spread the word out. You will have to share it, to speak about it, to advertise it if necessary.
Here are some tips how to increase the chances more people to be attracted by your campaign and to support you.
You really have to be clear with your concept and your idea because when people start asking questions, you will have to be able to explain what you do in a few words. People don't have all the time in the world. They will listen but not for too long.
Start with your friends
The best place to start is your friends, colleagues and people who know you. Share your campaign with them and ask for their support and help.
Share in social networks
You can share your campaign on social networks like Twitter, Facebook, LinkedIn, etc. This can attract supporters especially if you know Facebook or LinkedIn groups with people who might be interested in what you do.
Networking and events
If you visit events or clubs for people with common interests, this can be the best moment to share your idea. People sometimes are "thirsty" for new movements, projects and things.
Writing a good article in a blog which is regularly visited by many people is a really good way to reach out a wider audience. Contact bloggers or ask your friends, they may know someone who can help.
It is really up to you to follow this approach, but if you want, you can also use different advertising channels.
There are many approaches and they depend on your imagination or the specific tools which you have in your hands. Another good piece of advice is to sit down and to think carefully about what else can be done in order to make your campaign popular.